JP2007288024A - Sensor chip, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-quality sensor chip which is small and excellent in durability, and to provide a manufacturing method for easily manufacturing such a sensor chip. <P>SOLUTION: The sensor chip is provided with a sensor body and a protective material, and the sensor body has a plurality of terminals on an active plane provided on one plane of a silicon substrate, and on a plane opposite to the active plane through an external region of the active plane or a front and rear surface conducting via. The protective material integrally has a corridor-like convex on its one surface, and the concave of the protective material is anode-bonded on the silicon substrate on the external region of the active plane of the sensor body. Thus, the active plane can be sealed with the protective material through a desired gap, and further, the protective material opposite to the sensor body can have an area not larger than the area of the sensor body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sensor chip, and more particularly, to a sensor chip provided with a protective material on the active surface side of a sensor body such as an image sensor such as a CCD or CMOS, or an acceleration sensor, and a method for easily manufacturing the sensor chip.

For example, an image sensor such as a CCD or CMOS generally has an active surface in which a color filter layer and a condensing lens are arranged on an array of a plurality of fine light receiving portions (pixels), and an area outside the active surface. In addition, a plurality of terminals for sending signals to the outside are provided. In a sensor chip having such an image sensor, a transparent protective material is provided to protect the active surface of the image sensor. In order to allow a desired gap to be present between the protective material and the active surface, the periphery of the active surface is molded with a resin, or a projection frame made of an insulating resin is interposed. (Patent Documents 1 and 2)
JP-A-3-155671 JP-A-6-204442

However, if the pressure when fixing the protective material to the image sensor is large, the resin member such as the projection frame may spread and the active surface and terminals may be covered. If the pressure at the time of adhering to the sensor is too small, adhesion failure occurs, and there is a problem that moisture penetrates into the gap between the active surface and the protective material in a subsequent process or the like. In addition, there is a problem in that the size of the gap between the active surface and the protective material varies depending on the degree of pressure when the protective material is fixed to the image sensor.
Furthermore, in a conventional resin member such as a protruding frame, for example, when a protective material is fixed under reduced pressure, the pressure in the gap between the active surface and the protective material becomes smaller than the external pressure, and acts on the resin member from the outside. There is also a problem that deformation or the like is caused by the applied pressure, and there is a possibility that moisture, dust, or the like may enter the gap portion together with the gas.

Further, the conventional sensor chip has a protective material larger than that of the sensor body, which hinders downsizing of the sensor chip itself and further downsizing of the electronic device incorporating the sensor chip.
The present invention has been made in view of the above circumstances, and provides a high-quality sensor chip that is small and excellent in durability, and a manufacturing method for easily manufacturing such a sensor chip. Objective.

  In order to achieve such an object, the sensor chip according to the present invention has an active surface provided on one surface of a silicon substrate and a region opposite to the active surface through an outer region of the active surface or front and back conductive vias. A sensor body having a plurality of terminals on the surface, and a protective material integrally having a corridor-shaped convex portion on one surface and sealing the active surface through a desired gap, the protective material, The convex portion is anodically bonded to the silicon substrate in the outer region of the active surface of the sensor body, and the area of the protective material facing the sensor body is equal to or less than the area of the sensor body. did.

As another aspect of the present invention, the corridor-shaped convex portion is configured to have a height of 2 to 100 μm and a width of 50 to 500 μm.
As another aspect of the present invention, the protective material is glass, and a Si—O bond between a silicon atom constituting the silicon substrate and an oxygen atom constituting the convex portion is formed at a bonding interface between the silicon substrate and the convex portion. It was set as the structure which exists.
As another aspect of the present invention, the protective material is configured to have at least one of an infrared cut filter, an antireflection film, and a low-pass filter.

  The sensor chip manufacturing method of the present invention includes a step of forming a sensor body by forming an active surface and a plurality of terminals located in an outer region of the active surface on one surface of a silicon substrate, and a corridor on one surface. Forming the protective material having a convex portion of the shape, and anodic bonding the convex portion to the silicon substrate between the active surface of the sensor main body and the terminal forming region, and the protective material on the sensor main body And a step of arranging.

  The sensor chip manufacturing method of the present invention includes a step of forming a sensor body by forming an active surface on one surface of a silicon substrate and a plurality of terminals on the other surface of the silicon substrate via front and back conductive vias. And forming a protective material having a corridor-shaped convex portion on one surface, and anodic bonding the convex portion to the silicon substrate in an outer region of the active surface of the sensor body, thereby attaching the protective material to the sensor. And a step of disposing on the main body.

As another aspect of the present invention, in the step of forming the protective material, the convex portion is formed by polishing and / or etching one surface of the protective material in a grid pattern.
As another aspect of the present invention, the convex portion is formed by polishing one surface of the protective material in a grid pattern to form a concave portion, and then etching and flattening the concave portion. The configuration.
As another aspect of the present invention, in the step of forming the protective material, the protective material is melted, injected into a mold, and solidified to form the protective material.
As another aspect of the present invention, the mold is configured to use a carbon mold.

  In such a sensor chip of the present invention, the protective material integrally having the convex portion is anodically bonded to the silicon substrate constituting the sensor body, so the protective material is firmly disposed on the sensor body, In addition, since the mechanical strength of the protective material is high, even if there is a difference between the pressure and the external pressure in the gap between the active surface and the protective material, the active surface can be reliably sealed, and the durability is extremely high. Since the gap between the active surface and the protective material can be controlled by the height of the convex portion, the gap accuracy is high, and since the area of the protective material is less than the area of the sensor body, the size of the sensor chip is small. It is the same size as the sensor body, and the sensor chip can be significantly downsized compared to the conventional size.

  Further, in the method of manufacturing the sensor chip of the present invention, when the protective material is disposed on the sensor main body via the convex portion, the convex portion is bonded to the silicon substrate constituting the sensor main body by anodic bonding. It can be joined with high strength, and no adhesive is used for joining, so there is no covering of the active surface and terminals due to spreading of the adhesive, and even if the applied pressure fluctuates during joining of the protective material In addition, since the mechanical strength of the convex part is large and there is almost no deformation, it is possible to prevent the active surface and terminals from being adversely affected, and at the same time, it is easy to make the gap between the active surface of the sensor body and the protective material uniform. In addition, after a protective material integrally provided with a convex portion having a desired height is disposed on the sensor body, only unnecessary portions of the protective material are polished without damaging the sensor body. Removed to it is also possible to a small area, thereby a small high durability, the production of high quality of the sensor chip enables.

Embodiments of the present invention will be described below with reference to the drawings.
[Sensor chip]
1 and 2 are schematic cross-sectional views showing an embodiment of the sensor chip of the present invention. 1 and 2, the sensor chip 1 of the present invention includes a sensor body 2 and a protective material 5. The sensor body 2 has an active surface 2A on one surface of a silicon substrate 3, and the active surface 2A. The outer region includes a plurality of terminals 4 arranged via wiring 4a, and the protective material 5 has a corridor-shaped convex portion 6 integrally on one surface. FIG. 2 is a cross-sectional view of a portion where the wiring 4a and the terminal 4 are not present. The protective material 5 is disposed in the sensor body 2 by the convex portion 6 being anodically bonded to the silicon substrate 3 in the region between the active surface 2 </ b> A and the terminal 4. This protective material 5 is opposed to the active surface 2A of the sensor body 2 through a desired gap 7, and seals the gap 7 together with the convex portion 6 to protect the active surface 2A.

  FIG. 3 is a view for explaining the corridor-shaped convex portion 6 integrally provided on one surface of the protective material 5. In the present invention, the convex portion 6 may have an independent corridor shape as shown by hatching in FIG. 3A, and as shown by hatching in FIG. Alternatively, it may have a corridor shape composed of a plurality of line-shaped convex portions 6a and convex portions 6b orthogonal to the lattice shape. The above-mentioned hatched corridor shape may be either a square or a rectangle, and may be a rhombus, a parallelogram, a circle, an ellipse or the like if necessary. The above-mentioned “integral” means that the protective material 5 and the convex portion 6 are made of the same material, and the convex portion 6 is formed simultaneously with the formation of the protective material 5.

  4 and 5 are schematic sectional views showing other embodiments of the sensor chip of the present invention. 4 and 5, the sensor chip 11 of the present invention includes a sensor body 12 and a protective material 15. The sensor body 12 has an active surface 12A on one surface of the silicon substrate 13 and a plurality of wirings 14a drawn to the outer region of the active surface 12A, and is connected to each wiring 14a through the front and back conductive vias 18. The plurality of terminals 14 are provided on the back surface (surface opposite to the active surface 12A) of the silicon substrate 13. Further, the protective material 15 has a corridor-shaped convex portion 16 integrally on one surface, and this protective material 15 is formed by anodically bonding the convex portion 16 to a region outside the active surface 12A. The sensor body 12 is disposed. The protective material 15 is opposed to the active surface 12A of the sensor main body 12 with a desired gap 17 therebetween, and seals the gap 17 together with the convex portion 16 to protect the active surface 12A. 5 is a cross-sectional view of a portion where the wiring 14a, the terminal 14, and the front and back conductive vias 18 are not present. Moreover, the corridor shape of the convex part 16 in the sensor chip 11 may be either of FIG. 3 (A) and FIG. 3 (B) similarly to the convex part 6 in the sensor chip 1 described above.

Further, as shown in FIG. 4 and FIG. 5, as a sensor chip 11 having terminals 14 on the back surface through front and back conductive vias 18, as shown in FIG. 6, wiring 14a is formed below the corridor-shaped convex portion 16. The front and back conductive vias 18 may be connected, and the terminal 14 may be located below the convex portion 16. With such a structure, the sensor chip 11 can be further reduced in size.
The sensor bodies 2 and 12 constituting the sensor chips 1 and 11 of the present invention are image sensors such as CCD and CMOS formed on the silicon substrates 3 and 13, various MEMS (Micro sensors such as an acceleration sensor, a pressure sensor, and a gyro sensor). Electromechanical System) sensor or the like. In addition, the active surfaces 2A and 12A of the sensor bodies 2 and 12 mean regions that exhibit a desired detection function of the sensor, such as a region in which light receiving elements that perform photoelectric conversion are arranged to form a plurality of pixels. .

  The plurality of terminals 4 and 14 included in the sensor bodies 2 and 12 are terminals for sending signals to the outside. In the sensor chip 11, these terminals 14 are connected to the back surface of the sensor body 12 through front and back conductive vias 18. The material of the terminals 4 and 14 and the wirings 4a and 14a can be a conductive material such as aluminum, copper, silver, gold, or nickel, and may have a laminated structure of a plurality of types of conductive materials. The material of the front and back conductive vias 18 may be a conductive material such as copper, silver, gold, or tin, or a conductive paste containing these conductive materials.

  The protective members 5 and 15 constituting the sensor chips 1 and 11 of the present invention have corridor-shaped protrusions 6 and 17 so as to form gaps 7 and 17 between the active surfaces 2A and 12A of the sensor bodies 2 and 12, respectively. 16 is anodically bonded to the silicon substrates 3 and 13. The material of the protective members 5 and 15 is glass. The glass in the present invention is an amorphous solid containing silicon dioxide as a main component and optionally containing an oxide such as boron or sodium as a subcomponent, for example, borosilicate glass, quartz glass, quartz, Examples include sapphire and fluorite. In particular, borosilicate glass (LEBG) such as Tempax (B33) manufactured by Schott and Pyrex manufactured by Corning having a thermal expansion coefficient of about 3 ppm / K is preferable.

For anodic bonding of the projections 6 and 16 to the silicon substrates 3 and 13, for example, a voltage of about 400 to 1000 V is applied between the silicon substrates 3 and 13 and the protective materials 5 and 15 at a temperature of 200 to 500 ° C. Is done. As a result, Si—O bonds are generated between the silicon atoms constituting the silicon substrates 3 and 13 and the oxygen atoms constituting the convex portions 6 and 16, and both are firmly bonded.
Further, the protective materials 5 and 15 are obtained by adding an infrared absorbing material to a glass material to give an infrared absorbing function, and an infrared absorbing film on the surface (opposite the surface on which the convex portions 6 and 16 are provided). It may be provided, or may further include at least one of an antireflection film and a low-pass filter. The size of the protective members 5 and 15 (the size of the surface facing the sensor main bodies 2 and 12) is equal to or smaller than the area of the sensor main bodies 2 and 12. In the example shown in FIGS. 1 and 2, the protective material 5 exists inside the region where the terminal 4 of the sensor body 2 is formed, and the terminal 4 is exposed.

The thickness of the protective materials 5 and 15 (the thickness of the portion where the convex portions 6 and 16 do not exist) can be set in the range of 0.2 to 0.5 mm, for example, in consideration of the material, light transmittance, and the like. . Moreover, the thickness of the gaps 7 and 17 existing between the protective members 5 and 15 and the active surfaces 2A and 12A of the sensor bodies 2 and 12 can be set in the range of 2 to 100 μm, for example.
Corridor-shaped convex portions 6 and 16 provided integrally with the protective members 5 and 15 are outside the active surfaces 2A and 12A of the sensor main bodies 2 and 12 and in regions inside the terminals 4 and 14. It has a size and shape that can be fixed. Note that, as in the example shown in FIG. 6, the formation region of the terminal 14 of the sensor body 12 and the position of the convex portion 16 of the protective material 15 may substantially coincide with each other. The region may be present inside the position of the convex portion 16 of the protective material 15.
The height and width of the projections 6 and 16 can be appropriately set in consideration of the thicknesses of the gaps 7 and 17. For example, the height is 2 to 100 μm and the width is 50 to 500 μm. Can be set by range.

  In the sensor chips 1 and 11 of the present invention as described above, since the protective materials 5 and 15 having the convex portions 6 and 16 are anodically bonded to the silicon substrates 3 and 13, the protective materials 5 and 15 are Since the protective members 5 and 15 are firmly disposed on the sensor bodies 2 and 12 and the mechanical strength of the protective members 5 and 15 is high, the pressure in the gaps 7 and 17 between the active surfaces 2A and 12A and the protective members 5 and 15 Even if a difference from the external pressure occurs, the active surfaces 2A and 12A can be reliably sealed, and the durability is extremely high. Furthermore, since the gaps 7 and 17 between the active surfaces 2A and 12A and the protective materials 5 and 15 can be controlled by the height of the convex portions 6 and 16, uniform gap accuracy is possible. Moreover, since the area of the protective members 5 and 15 is equal to or smaller than the area of the sensor bodies 2 and 12, the size of the sensor bodies 2 and 12 becomes the size of the sensor chips 1 and 11 as they are. Can be miniaturized.

The sensor chip of the present invention can be connected to and mounted on another substrate or the like using the terminals 4 and 14 or the back surface (surface where the active surface 12A does not exist) side of the front and back conductive via 18. For example, the sensor chip 1 shown in FIGS. 1 and 2 can be mounted on the substrate 21 provided with the opening 22 and the wiring 23 via the bumps 24 in the form shown in FIG. In the illustrated example, after the sensor chip 1 is mounted, the insulating material 25 is poured into the opening 22 of the substrate 21 and sealed, but at this time, the active surface 2A ( The insulating material 25 is prevented from flowing into the gap 7).
The sensor chip described above is an example, and the present invention is not limited to these embodiments.

[Method for manufacturing sensor chip]
Next, a method for manufacturing the sensor chip of the present invention will be described.
FIG. 8 is a process diagram showing an embodiment of the sensor chip manufacturing method of the present invention, taking the sensor chip 1 shown in FIGS. 1 and 2 as an example. 8 will be described with reference to FIG. 1 described above.
First, the sensor main body 2 is produced by applying multiple faces to the silicon wafer 31 (FIG. 8A). The sensor body 2 can be manufactured using a conventionally known method such as a MEMS (Micro Electromechanical System) method, a photodiode manufacturing method (semiconductor process), or the like. The produced sensor body 2 has an active surface 2A on the surface, and has a plurality of terminals 4 in the region outside the active surface 2A via wirings 4a.

  On the other hand, the concave portion 5a is formed on one surface of the base material 5 'for forming the protective material 5, and the protective material 5 integrally having the corridor-shaped convex portion 6 is formed (FIG. 8B). As the substrate 5 ', glass (amorphous solid containing silicon dioxide as a main component and optionally containing an oxide such as boron or sodium as a subcomponent) can be used. For example, examples of the base material 5 'include borosilicate glass, quartz glass, crystal, sapphire, and fluorite. In particular, borosilicate glass (LEBG) such as Tempax (B33) manufactured by Schott and Pyrex manufactured by Corning having a thermal expansion coefficient of about 3 ppm / K can be preferably used. Further, the base material 5 'is a glass material containing an infrared absorbing material to give an infrared absorbing function, an infrared absorbing film disposed on the surface (the surface opposite to the surface on which the convex portions 6 are provided), Furthermore, you may have at least 1 sort (s) of an antireflection film and a low-pass filter.

The concave portion 5a is formed on the base material 5 ′ by, for example, forming a resist pattern for forming the convex portion 6 on one surface of the base material 5 ′, and forming the resist pattern on the base material 5 ′ via the resist pattern. It can be performed by sand blasting or the like, or wet etching or dry etching. Further, grinding and etching may be combined. For example, the convex portion 6 is first formed by grinding, and then the surface of the concave portion 5a (including the surface facing the active surface 2A) is etched and flattened. The thickness of the protective material 5 can be made uniform.
Moreover, you may form the protective material 5 which has the convex part 6 integrally by fuse | melting glass, injecting into a metal mold | die, and solidifying. The melting temperature can be appropriately set according to the material of the glass used. There is no particular limitation on the mold to be used, but in consideration of the fact that the thermal expansion coefficient between the glass and the mold is close, and the convex portion 6 having a fine shape can be formed without accumulating strain stress inside, the carbon mold is used. It is preferred to use a mold.

Next, the protective material 5 is disposed on the sensor main body 2 by anodically bonding the convex portion 6 to the silicon wafer 31 in the outer region of the active surface 2A in each impositioned sensor main body 2 (FIG. 8 ( C)). In the anodic bonding of the convex portion 6 to the silicon wafer 31, for example, a voltage of about 400 to 1000 V is applied between both electrodes at a temperature of 200 to 500 ° C. with the silicon wafer 31 as an anode and the protective material 5 as a cathode. As a result, at the interface between the silicon wafer 31 and the convex portion 6, Si—O bonds are generated between the silicon atoms constituting the silicon wafer 31 and the oxygen atoms constituting the convex portion 6, and strong anodic bonding is achieved. Done. In the step of disposing the protective material 5, the convex portion 6 is provided integrally with the protective material 5, and since no adhesive is used, the pressure is increased in order to obtain good adhesion. In addition, there are no fluctuations in the gap 7 due to the deformation of the convex portion 6 and no adverse effects due to the adhesive coating on the active surface 2A and the terminals 4.
Note that the wiring 4a is disposed on the silicon wafer 31, but since the wiring 4a is usually thin (for example, 1 μm or less), the protective material 5 is provided at a portion where the wiring 4a does not exist. It is possible to reliably anodically bond the convex portion 6 to the silicon wafer 31.

Next, unnecessary portions of the protective material 5 are polished and removed, and the protective material 5 is fixed to each sensor body 2 (FIG. 8D). The protective material 5 can be polished by, for example, using a diamond cutter and stopping grinding (dimension cut) just before the diamond cutter contacts the silicon wafer 31. In the illustrated example, the protective material 5 is polished so that the terminal 4 of each sensor body 2 is exposed. In the present invention, by appropriately controlling the thickness of the base material 5 ′ before the formation of the convex portion 6 and the degree of polishing and etching at the time of forming the convex portion, or by the die design, the convex portion having a desired height. 6 can be formed, so that after the protective material 5 is disposed on the sensor body, only unnecessary portions of the protective material 5 are polished and removed without damaging the sensor body 2 to form the protective material 5 having a small area. it can.
Next, each sensor chip 1 can be obtained by dicing the silicon wafer 31 (FIG. 8E).

FIG. 9 is a process diagram showing another embodiment of the sensor chip manufacturing method of the present invention, taking the sensor chip 11 shown in FIGS. 4 and 5 as an example. Note that FIG. 9 will be described with reference to FIG. 4 described above.
First, the sensor main body 12 is produced by applying multiple faces to the silicon wafer 41 (FIG. 9A). The sensor body 12 can be produced in the same manner as the sensor body 2 described above. The produced sensor body 12 has an active surface 12A on the surface 41a of the silicon wafer 41, and is formed in a region outside the active surface 12A. It has a plurality of lead lines 14a to reach.

Next, a fine through hole 19 is formed at the tip portion of the wiring 14 a of each sensor body 12, and a conductive material is disposed in the fine through hole 19 to form a front and back conductive via 18, and a terminal connected to each front and back conductive via 18 14 is formed on the back surface 41b of the silicon wafer 41 (FIG. 9B).
The fine through-hole 19 is formed, for example, by forming a mask pattern on the back surface 41 b of the silicon wafer 41 and applying ICP-RIE (Inductively Coupled Plasma-Reactive), which is a dry etching method using plasma to the exposed silicon wafer 41. (Ion Etching: inductively coupled plasma-reactive ion etching). Further, the fine through holes 19 can be formed by a sand blast method, a wet etching method, or a femtosecond laser method. The opening diameter of the fine through hole 19 can be set in the range of 30 to 80 μm, for example.

In addition, the conductive material is disposed in the fine through hole 19 by, for example, forming a base conductive thin film in the fine through hole 19 by a plasma CVD method or the like and then depositing a metal by electrolytic filling plating. Can do. Alternatively, the front and back conductive vias 18 can be formed by filling the conductive paste into the fine through holes 19.
When the sensor chip 11 shown in FIG. 6 is manufactured, the length of the wiring 14a is shortened and the formation position of the fine through hole 19 is set closer to the active surface 12A than in the above example.
On the other hand, the concave portion 15a is formed on one surface of the base material 15 'for forming the protective material 15, or the molten glass is injected into a mold and solidified to integrate the corrugated convex portion 16 together. Thus, the protective material 15 is formed (FIG. 9C). The method of forming such a protective material 15 and the material to be used can be the same as those of the protective material 5 described above.

Next, in each sensor surface 12 of each imposition, the protective material 15 is disposed on the sensor body 12 by anodically bonding the convex portion 16 to the silicon wafer 41 in the outer region of the active surface 12A (FIG. 9D). )). The anodic bonding of the convex portion 16 to the silicon wafer 41 can be performed in the same manner as the anodic bonding of the convex portion 6 to the silicon wafer 31 described above. In the step of disposing the protective material 15, the convex portion 16 is provided integrally with the protective material 15, and since no adhesive is used, the pressure is increased in order to obtain good adhesion. However, there is no adverse effect due to the variation of the gap 17 due to the deformation of the convex portion 16 or the adhesive coating on the active surface 12A and the terminal 14.
Next, the protective material 15 and the silicon wafer 41 are diced to obtain individual sensor chips 11 (FIG. 9E).

The sensor chip manufacturing method of the present invention as described above has the active surfaces 2A and 12A and terminals even when the pressure changes greatly when the protective members 5 and 15 are anodically bonded via the convex portions 6 and 16. 4 and 14 are not covered by the deformation of the convex portions 6 and 16, and the gap between the active surfaces 2A and 12A of the sensor bodies 1 and 11 and the protective materials 5 and 15 is uniform, and durability is improved. High, small and high quality sensor chips can be manufactured.
In addition, the manufacturing method of the sensor chip of the above-mentioned this invention is an illustration, and this invention is not limited to these embodiment.

Next, the present invention will be described in more detail with specific examples.
[Example 1]
First, a silicon wafer having a thickness of 625 μm was prepared, and was divided into multiple faces with a size of 5 mm × 7 mm. Next, for each imposition of the silicon wafer, a sensor body (active surface dimensions: 3.88 mm × 5.88 mm) is produced by a conventional method, and then back grinding is performed from the back surface of the silicon wafer to a thickness of 500 μm. It was. Each sensor body was provided with 20 terminals around the active surface.

  On the other hand, a glass substrate (compliant with 6-inch JEIDA standard silicon wafer dimensions) having a thickness of 550 μm was prepared. Next, a chromium film pattern was formed on one surface of the glass substrate (to improve adhesion), and a pattern was formed with an acid resistant resist (manufactured by Tokyo Ohka Kogyo Co., Ltd.) to obtain a mask. As a result, within each imposition of a 5 mm × 7 mm grid, stripes having a width of 100 μm intersect in a lattice pattern, and a 3.9 mm × 5.9 mm rectangular pattern non-formation site exists at the center of each imposition. Thus, a mask pattern was formed. Next, the glass substrate is wet etched by spraying hydrofluoric acid through the mask pattern, and then the mask pattern is removed using a resist stripper and a chromium stripper (both manufactured by Tokyo Ohka Kogyo Co., Ltd.). did. As a result, a convex portion having a corridor shape (4 mm × 6 mm) having a height of 50 μm and a width of 100 μm was formed to obtain a protective material.

Next, an electrode (cathode) was connected to the surface opposite to the surface on which the convex portions of the protective material were formed, and an electrode (anode) was connected to the silicon wafer. Next, the convex part is brought into contact with an intermediate region between the active surface of the sensor body and the region where the terminals are disposed, and in this state, an anodic bonding apparatus (AB-40L manufactured by Ayumi Industry Co., Ltd.) is used. The sample was heated to 400 ° C., and a voltage of 500 V was applied between the electrodes (10 minutes) to perform anodic bonding. Thereby, the protective material was disposed on the sensor body. The gap between the provided protective material and the active surface of each sensor body was about 50 μm.
Next, using a diamond cutter, only the glass substrate at the boundary portion of each sensor body was ground and removed with a width of 1 mm. Thereby, it came to the state by which the protective material which consists of a glass substrate of 4 mm x 6 mm was arrange | positioned on the frame for sealing.

Next, the silicon wafer was diced with a diamond cutter to obtain the sensor chip of the present invention. This sensor chip had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small.
In addition, as a result of measuring the interface between the protective material of each sensor chip and the silicon substrate (silicon wafer) with a transmission electron microscope (TEM), Si− of silicon atoms constituting the silicon substrate and oxygen atoms constituting the convex portion was obtained. It was confirmed that an O bond was present.

[Example 2]
In the same manner as in Example 1, a sensor main body was produced by applying multiple faces to a silicon wafer to obtain a wafer level sensor main body. Each sensor body was provided with 20 wiring pads around the active surface.

Next, a silicon nitride film (thickness 5 μm) was formed on the silicon wafer surface opposite to the active surface by plasma CVD. Next, a positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied to the entire surface of the silicon nitride film, and exposed and developed through a photomask for forming fine through holes, thereby forming a resist pattern. Formed. Next, the silicon nitride film exposed from the resist pattern was dry-etched using CF ₄ as an etching gas, and then the resist pattern was peeled off to form a mask pattern made of silicon nitride on each surface. In the mask pattern, 20 circular openings having a diameter of 100 μm were formed so as to correspond to the wiring pads for each imposition.

Next, the silicon wafer exposed from the mask pattern was dry-etched with an ICP-RIE apparatus using SF ₆ as an etching gas to form fine through holes. This fine through-hole has a tapered shape with one opening diameter of 80 μm and the inner opening diameter of 40 μm, and the wiring pad is exposed in the inner part.

  Next, the mask pattern was removed from the core material using acetone. Thereafter, a silicon nitride film was formed by a plasma CVD method in the fine through hole and on the silicon wafer surface opposite to the active surface, and a titanium nitride film was further formed by an MOCVD method to form an insulating film. Thereafter, a base conductive thin film having a thickness of 0.3 μm was formed from one surface of the silicon wafer (the side opposite to the active surface) by sputtering in the order of titanium-copper. Next, a dry film resist (APR manufactured by Asahi Kasei Co., Ltd.) was laminated on the underlying conductive thin film. Next, the resist pattern (thickness 15 μm) was formed by exposure and development through a photomask for forming front and back conductive vias. Using this resist pattern as a mask, the above-mentioned underlying conductive thin film was used as a power feeding layer, and electrolytic copper plating was performed to fill the inside of the fine through hole. Next, the resist pattern and the underlying conductive thin film were removed to form front and back conductive vias.

On the other hand, a glass substrate (compliant with 6-inch JEIDA standard silicon wafer dimensions) having a thickness of 550 μm was prepared. Next, a dry film resist (Liston A3100 manufactured by DuPont) having a thickness of 25 μm is laminated on one surface of the glass substrate using a laminating apparatus (MACH-600 manufactured by Hakuto Co., Ltd.), and 100 mJ / cm through a predetermined mask. Exposed at ² . Then, it developed with 1% sodium carbonate aqueous solution. As a result, within each imposition of a 5 mm × 7 mm grid, stripes having a width of 100 μm intersect in a lattice pattern, and a 3.9 mm × 5.9 mm rectangular pattern non-formation site exists at the center of each imposition. Thus, a mask pattern was formed. Next, sandblasting is performed on the glass substrate through the above mask pattern, and then flattening is performed by spraying and etching hydrofluoric acid, and then the mask pattern is removed using a 5% aqueous sodium hydroxide solution. did. As a result, a convex portion having a corridor shape (4 mm × 6 mm) having a height of 50 μm and a width of 100 μm was formed and used as a protective material.

Next, the tip of the convex portion of the protective material was brought into contact with an intermediate region between the active surface of the sensor body and the region where the wiring pads were disposed, and anodic bonding was performed under the same conditions as in Example 1. . Thereby, the protective material was disposed on the sensor body. The gap between the provided protective material and the active surface of each sensor body was about 50 μm.
Next, the silicon wafer and the glass substrate were diced with a diamond cutter to obtain the sensor chip of the present invention. This sensor chip had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small.
In addition, as a result of measuring the interface between the protective material of each sensor chip and the silicon substrate (silicon wafer) with a transmission electron microscope (TEM), Si− of silicon atoms constituting the silicon substrate and oxygen atoms constituting the convex portion was obtained. It was confirmed that an O bond was present.

[Example 3]
A sensor chip of the present invention was obtained in the same manner as in Example 1 except that a protective material integrally having convex portions was produced as follows.
That is, as the protective material, glass powder (Tempax manufactured by Schott) was melted at 600 ° C., injected into a carbon mold, cooled to 500 ° C. or less, and taken out from the carbon mold, and then 25 ° C. It was produced by cooling to. The produced protective material is provided with a convex portion having a corridor shape (4 mm × 6 mm) having a height of 50 μm and a width of 100 μm in each imposition of a 5 mm × 7 mm grid, and at a portion where no convex portion exists. The thickness was 500 μm.
The obtained sensor chip of the present invention had a size of 4.8 mm × 6.8 mm, a height of about 1.1 mm, and was extremely small.
In addition, as a result of measuring the interface between the protective material of each sensor chip and the silicon substrate (silicon wafer) with a transmission electron microscope (TEM), Si − of silicon atoms constituting the silicon substrate and oxygen atoms constituting the convex portion was obtained. It was confirmed that an O bond was present.

  The present invention can be applied in various fields where a small and highly reliable sensor chip is required.

It is a schematic sectional drawing which shows one Embodiment of the sensor chip of this invention. It is a schematic sectional drawing which shows one Embodiment of the sensor chip of this invention. It is a figure for demonstrating the corridor-shaped convex part with which the protective material was equipped. It is a schematic sectional drawing which shows other embodiment of the sensor chip of this invention. It is a schematic sectional drawing which shows other embodiment of the sensor chip of this invention. It is a schematic sectional drawing which shows other embodiment of the sensor chip of this invention. It is a figure which shows the example by which the sensor chip of this invention is mounted in a board | substrate. It is process drawing which shows one Embodiment of the manufacturing method of the sensor chip of this invention. It is process drawing which shows other embodiment of the manufacturing method of the sensor chip of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Sensor chip 2,12 ... Sensor main body 2A, 12A ... Active surface 3,13 ... Silicon substrate 4,14 ... Terminal 5,15 ... Protective material 6,16 ... Convex part 7, 17 ... Gap 18 ... Front and back conduction Via 19 ... Fine through hole

Claims (10)

  An active surface provided on one surface of the silicon substrate, a sensor body having a plurality of terminals on the outer surface of the active surface or a surface opposite to the active surface through front and back conductive vias, and a corridor-shaped convex portion And a protective material that is integrally formed on one surface and seals the active surface through a desired gap. The protective material has a convex portion in the outer region of the active surface of the sensor body. A sensor chip, wherein the area of the protective material facing the sensor body is an area equal to or less than the area of the sensor body.   The sensor chip according to claim 1, wherein the corridor-shaped convex portion has a height in a range of 2 to 100 μm and a width in a range of 50 to 500 μm.   The protective material is glass, and a Si-O bond between a silicon atom constituting the silicon substrate and an oxygen atom constituting the convex portion exists at a bonding interface between the silicon substrate and the convex portion. Item 3. The sensor chip according to item 1 or item 2.   The sensor chip according to any one of claims 1 to 3, wherein the protective material includes at least one of an infrared cut filter, an antireflection film, and a low-pass filter. Forming a sensor body by forming an active surface and a plurality of terminals located in an outer region of the active surface on one surface of the silicon substrate;
Forming a protective material having a corridor-shaped convex portion on one surface;
And a step of disposing the protective material on the sensor body by anodically bonding the convex portion to the silicon substrate between the active surface of the sensor body and a terminal formation region. Chip manufacturing method. Forming a sensor body by forming an active surface on one surface of a silicon substrate and forming a plurality of terminals on the other surface of the silicon substrate via front and back conductive vias;
Forming a protective material having a corridor-shaped convex portion on one surface;
And a step of disposing the protective material on the sensor body by anodically bonding the convex portion to the silicon substrate in an outer region of the active surface of the sensor body. .   7. The step of forming the protective material, the convex portion is formed by polishing and / or etching one surface of the protective material in a grid pattern. Manufacturing method of sensor chip.   The said convex part is formed by grind | polishing one surface of the said protective material in a grid shape, forming a recessed part, and etching and planarizing this recessed part after that. Sensor chip manufacturing method.   The sensor chip according to claim 5 or 6, wherein, in the step of forming the protective material, the protective material is formed by melting and injecting the raw material of the protective material into a mold and solidifying. Manufacturing method.   The method of manufacturing a sensor chip according to claim 9, wherein a carbon mold is used as the mold.

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